* Remove the NGraph engine from PDPD repository
1. Each operator was removed from the operator's directory
2. Each test was removed from the unittest directory
3. The parallel executor support was removed from the PDPD
4. The CMake file was removed from the PDPD
5. The NG flags were removed from the repository
test=develop

* Remove ngraph from:
1. Cmake file
2. Python file
test=develop

error message enhancement for repeated fc

fill op error message enhancement

* OP (recurrent) error message enhancement

* add randint op

* Make optimizer consistent in dygraph and static-graph and remove some LOG-INFO

* add support for value tensor support of fill_constant Op

* add index_sample op

* static model runner basic implement, test=develop

* add run program op to execute loaded program, test=develop

* refactor static model runner & run program op, test=develop

* reset engine.cc to resolve conflict

* adapt the change of dygraph double grad, test=develop

* refactor impl to solve control flow error, test=develop

* clear debug code, test=develop

* fix ci str compatible error & checkout dygraph grad maker & add example, test=develop

* hide api & add op test, test=develop

* fix run program op test places error, test=develop

* fix program by review comment, test=develop

* delete change var desc name, test=develop

* fix other program by review comment, test=develop

* remove _static_graph_guard, test=develop

* add selectedrows test, test=develop

* remove desc parser, test=develop

* fix detail program, test=develop

* change socpe create & add test, test=develop

* fix inplace_abn windows compile error. test=develop

This reverts commit abe3e690.
test=develop

* Add the sum op to API 2.0, test=develop
* Fix the import meesage in common_ops_import

add tril op and  triu op

* add unbind op
unbind(tensor, dim=0):
说明：移除指定维后，返回一组数组，包含了沿着指定维切片后的各个切片。

tensor(Tensor) -- 输入Tensor
dim(int) -- 删除的维度

示例：
 Input = [[1,2],
           [3,4],
           [5,6]]
  axis = 0
  Output[0] = [1,2]
  Output[1] = [3,4]
  Output[2] = [5,6]

* delete invalid check inferface Ref & VectorRef, test=develop

* fix vector ref delete error, test=develop

* try the new check inferface, test=develop

* change all related code with new check macro, test=develop

* remove static assert, test=develop

* polish detail, test=develop

* skip coverage problem, test=develop

* add new check macro, test=develop

* solve the conflict of ops with the same name. test=develop

* Add the argmax op to API 2.0, test=develop

* Fix the compiler problem in arg_max op, test=develop

* Fix the import meesage in common_ops_import, test=develop

* Fix the default dtype of arg_min_max, test=develop

Update the new api ops of creation ops to the api 2.0

* Add allclose Op, and its function is analogous to numpy.allclose. It returns True if two tensors are elementwise equal within a tolerance.

* sin sqrt tanh atan add out, test=develop

* optimize doc, test=develop

* add dygraph test, test=develop

* add tdm child op

* add flip op

* add functional conv

* add test and doc for function convs, test=develop

* update ConvTransposeOp's InferShape and error message, test=develop

* use global conv cache; test=develop

* use singleton cache; test=develop

* fix format error; test=develop

* add cudnn helper header; test=develop

* fix header error; test=develop

* fix mac unitest; test=develop

* fix mac unitest; test=develop

* fix file format; test=develop

* fix include file error, test=develop

* remove kernel_configs_ in class ExecutionContext and kernel_configs_map_ in class OperatorWithKernel, test=develop

* fix test_elementwise_mul_op_dim, test=develop

* fix compile error, test=develop
Co-authored-by: Nphlrain <phliuhongyu@126.com>

elementwise function used before definition then failed in cuda 8, move it ahead.

* update linspace, equal operators to API 2.0, test=develop

* equal support higher performance CUDA kernel, test=develop

* update comment of equal&linspace operator, test=develop

* update comment of equal&linspace operator, test=develop